1. Field of the Invention
The present invention generally relates to an electro-optical apparatus and, more particularly relates to a display panel.
2. Description of Related Art
FIG. 1A is a partial cross-sectional view of a conventional display panel. Referring to FIG. 1A, the display panel 110 includes a first substrate 120, a second substrate 130, a sealant 140, a plurality of ball spacers 150 (only one is shown in FIG. 1A), and a display medium layer 160. The first substrate 120 has a pixel array 120a and a peripheral circuit 120b connected to the pixel array 120a. The second substrate 130 is disposed above the first substrate 120. The sealant 140 is disposed between the first substrate 120 and the second substrate 130, and located on a portion of the peripheral circuit 120b. A conductive wiring structure 122 is disposed in the region of the peripheral circuit 120b covered with the sealant 140. The ball spacers 150 are disposed inside the sealant 140, for maintaining a gap g′ between the first substrate 120 and the second substrate 130.
As shown in FIG. 1A, an insulating layer PV′ is covered on the conductive wiring structure 122 for protecting the conductive wiring structure 122. In detail, as the sealant 140 contains water vapour and/or solvent, the conductive wiring structure 122 if directly contacting the sealant 140 may get corroded. Further, since the ball spacers 150 are rigid, the insulating layer PV′ disposed between the ball spacers 150 and the conductive wiring structure 122 may produce certain buffering effect, so as to reduce the external force applied on the conductive wiring structure 122.
In order to reduce the area of the peripheral circuit, the display panel is designed in the trend of slim border. However, as the area of the peripheral circuit gets narrower, the layout space of the conductive wiring structure is increasingly reduced. Therefore, the above conductive wiring structure of a single conductive layer is changed to be formed by double conductive layers, as shown in FIG. 1B.
FIG. 1B is a partial cross-sectional view of another conventional display panel. Referring to FIG. 1B, the display panel 110′ is similar to the display panel 110 in FIG. 1A, i.e., the ball spacers 150 are still disposed in the sealant 140. The main difference between the display panels in FIGS. 1A and 1B lies in that the conductive wiring structure in the display panel 110′ is a multi-layer conductive wiring structure 122′ constituted by the first conductive wirings 122a and the second conductive wirings 122b. An insulating layer GI′ is disposed between the first conductive wirings 122a and the second conductive wirings 122b so as to prevent the first conductive wirings 122a from being electrically connected to the second conductive wirings 122b. Another insulating layer PV′ is covered on the second conductive wirings 122b for protecting the second conductive wirings 122b. 
Meanwhile, referring to FIG. 1B, though the multi-layer conductive wiring structure 122′ is protected by the insulating layer PV′ covered thereabove, the ball spacers 150 may still damage the insulating layer PV′ under an excessive external force, and may even damage the multi-layer conductive wiring structure 122′ below the insulating layer PV′.